Motor/pump assembly for use in a braking device

ABSTRACT

A driven-side rotor shaft end of an electric motor is drive-connected to a drive-side pump shaft end of a pump via a coupling piece, in the manner of a cardan joint, in each case by means of the positive axial plug receptacle. The invention provides protection against torsional thrusts and axial vibrations, and a play-free drive by virtue of a conical design of the plug receptacle, at the same time with a mutual axial prestress of the rotor shaft end and pump shaft end.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of European application numberEP02004529.0 filed Feb. 27, 2002.

TECHNICAL FIELD

[0002] The invention relates to a motor/pump assembly, in particular toa motor vehicle braking device with the following features: A motor/pumpassembly for use in a coupling device for protection against torsionalthrusts and axial vibrations, said assembly comprising an electric motorhaving a driven-side rotor shaft, said shaft having an end; a pumphaving a drive-side pump shaft, said shaft having an end; and said rotorshaft end drive-connected via a joint to said pump shaft end, said jointincluding a coupling piece comprising an axially conical positive plugreceptacle for plugging at least one shaft end to provide a play-freerotational take-up.

BACKGROUND OF THE INVENTION

[0003] Motor vehicle braking devices are known, e.g., see EP 0 645 875B1. In a motor vehicle braking device, in particular for an ABS brakingdevice, the pump is normally designed as a hydraulic pump; in this case,pump plungers are driven by the pump shaft via eccentrics. The pumpshaft may be designed as a prolonged one-piece rotor shaft end of theelectric motor or be coupled as an independent pump component with apump shaft end to a corresponding rotor shaft end of the electric motorwhen the electric motor and pump are being assembled. For theintercoupling of the driven-side pump shaft end of the electric motor,on the one hand, to the drive-side pump shaft end of the pump, on theother hand, a coupling piece may be provided, which provides a driveconnection in the manner of a cardan joint to the rotor shaft end and tothe pump shaft end, in each case via a positive axial plug receptacle.

SUMMARY OF THE INVENTION

[0004] According to the object of the present invention, a driveconnection protected against undesirable torsional vibrations and axialthrusts is avoided in the case of drive connections of this type in themanner of a cardan joint, with an axially mutual positive plugreceptacle of the rotor shaft end and pump shaft end via a couplingpiece.

[0005] This object is achieved, according to the invention, by means ofa motor/pump assembly according to the following: an assembly for use inan antilock braking device to protect against torsional thrusts andaxial vibrations, said assembly comprising an electric motor having adriven-side rotor shaft, said shaft having a plugged end; a pump havinga drive-side pump shaft, said shaft having a plugged end; and a couplingdevice comprising a plug receptacle for receiving said plugged endsunder mutual prestress to provide for play-free rotational take-up.

[0006] Advantageous embodiments of the invention are the subject matterof the description to follow.

[0007] Proceeding from the recognition that torsional vibrations andaxial thrusts leading to premature damage are based particularly ontorque fluctuations of the pump and on a radial or axial tolerance playbetween those ends of the rotor shaft or pump shafts which are inpositive take-up in the coupling piece, the conicity according to theinvention, at the same time with slight mutual prestress of the rotorshaft end with respect to the pump shaft end, makes it possible bysimple means to eliminate production-related slack between the parts tobe driven in the coupling piece, and the freedom from play thereforeensured within the coupling piece makes it possible to avoid the torquefluctuations which occur as a result of movement and which penetrate viathe coupling piece into the motor and lead within the latter, forexample, to winding damage.

BRIEF DESCRIPTION OF THE FIGURES

[0008] The invention and further advantageous embodiments of theinvention according to the features of the subclaims are explained inmore detail below, by means of diagrammatic exemplary embodiments, inthe drawing in which:

[0009]FIG. 1 shows a fully mounted motor/pump assembly in an axialpart-sectional diagram;

[0010]FIG. 2 shows, in an enlarged detail from FIG. 1, the mutualrotational take-up connection, in the manner of a cardan joint, of therotor shaft end of the electric motor, on the one hand, and of the pumpshaft end of the pump, on the other hand, via a coupling piece;

[0011]FIG. 3 shows, in a perspectively enlarged detail from FIG. 2, aplug receptacle in the manner of a cardan joint, with a conical designof the flat take-up webs of the rotor shaft end and of the pump shaftend and with a design of the matching take-up grooves of the couplingpiece; and

[0012]FIG. 4 shows, in a perspectively enlarged detail from FIG. 2, aplug receptacle in the manner of a cardan joint, with a conical designof the take-up grooves of the coupling piece and with a design of theflat take-up webs of the rotor shaft end and of the pump shaft end.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013]FIG. 1 shows a complete motor/pump assembly capable of being used,for example, for a motor vehicle antilock braking device in an axialpart-sectional diagram. A pump 2 for a hydraulic brake fluid is flangedto an electric motor 1 on one end face and axially in alignment and theother end face of the pump 2 has mounted on it an electronic housing 3which receives a connection unit, in particular an electric orelectronic supply or control unit, not illustrated separately here, butknown, for example, from EP 0 695 875 B1, and which is connected via ajunction connection 1.1 to the control or supply connections of theelectric motor 1.

[0014] The electric motor 1 has a pump-side rotor shaft end 4 which canbe coupled via a coupling piece 6 to a pump shaft end 5 of the pump 2,for example when the electric motor 1 and the pump 2 are being assembledaxially.

[0015] As may be gathered from the enlarged detail according to FIG. 2and particularly according to FIGS. 3, 4, the rotational take-upcoupling between the rotor shaft end 4, on the one hand, and the pumpshaft end 5, on the other hand, takes place in the manner of a cardanjoint, in such a way that the rotor shaft end 4 can be plugged withprojecting flat take-up webs, in particular two-flat take-up webs'4.1;4.2, into corresponding take-up grooves, in particular two-flattake-up grooves 6.1;6.2, of the coupling piece 6 and the pump shaft end5 can be plugged with two-flat take-up webs 5.1;5.2 into matchingtake-up grooves, in particular two-flat take-up grooves 6.3;6.4, of thecoupling piece 6, said two-flat take-up grooves being offset relative toone another, for example, at 90° with respect to the first-mentionedtake-up grooves. Instead of the version illustrated in FIGS. 3, 4 in thereverse deign principle flat take-up webs may also be provided on thecoupling piece and matching two-flat take-up grooves may be provided onthe rotor shaft end and on the pump shaft end.

[0016] The rotor shaft end 4, on the one hand, or the pump shaft end 5can be plugged under slight mutual prestress into the positive plugreceptacle of the coupling piece 6.

[0017] According to the invention, as shown in FIG. 3, the two-flattake-up webs 4.1;4.2 and 5.1;5.2 have, on their take-up surfaces4.11;4.21 and 5.11;5.21 taking effect during rotational take-up andcoming to bear on the coupling piece 6, a conical design such that, dueto the mutual slight prestress, they come reliably into play-freebearing contact on the matching flat-running take-up surfaces of thetake-up grooves 6.1-6.4. The take-up surfaces are expediently providedwith a corresponding conical design with respect to both directions ofrotation.

[0018]FIG. 4 shows basically the same solution principle as thataccording to FIG. 3, but, in this case, the conical design is providedon the take-up surfaces 6.11-6.41, coming into take-up bearing contact,of the two-flat take-up grooves 6.1-6.4 of the coupling piece 6, and thetake-up surfaces of the two-flat take-up webs 4.1;4.2 and 5.1;5.2 of therotor shaft end 4 and of the pump shaft end 5 have a flat-running designwithout any separate machining as regards conicity.

What is claimed is:
 1. A motor/pump assembly for protection againsttorsional thrusts and axial vibrations, said assembly comprising: anelectric motor having a driven-side rotor shaft, said shaft having anend plugged with take-up webs; a pump having a drive-side pump shaft,said shaft having an end plugged with take-up webs; said rotor shaftplugged end connected to said pump shaft plugged end via an axialpositive plug receptacle for receiving the plugged shaft ends, saidreceptacle including take-up grooves having conical take-up contactsurfaces, wherein the connection provides a play-free rotationaltake-up.
 2. The motor/pump assembly as claimed in claim 1, wherein thebraking device is an antilock braking device.
 3. A motor/pump assemblyfor use in a motor vehicle antilock braking device, said assemblycomprising: an electric motor having a driven-side rotor shaft, saidshaft having an end plugged with take-up webs having conical contactsurfaces; a pump having a drive-side pump shaft, said shaft having anend plugged with take-up webs having conical contact surfaces; and acoupling device having take-up grooves for receiving said take-up websfor connecting said plugged ends under mutual prestress.
 4. Themotor/pump assembly as claimed in claim 3, wherein the connection isplay-free.
 5. An assembly for use in an antilock braking device toprotect against torsional thrusts and axial vibrations, said assemblycomprising: an electric motor having a driven-side rotor shaft, saidshaft having a plugged end; a pump having a drive-side pump shaft, saidshaft having a plugged end; a coupling device comprising a plugreceptacle for receiving said plugged ends under mutual prestress toprovide for play-free rotational take-up.
 6. The motor/pump assembly asclaimed in claim 5, wherein said plug receptacle comprises radiallyprojecting axially running take-up webs.
 7. The motor/pump assembly asclaimed in claim 5, wherein said ends are plugged with radiallyprojecting axially running take-up webs.
 8. The motor/pump assembly asclaimed in claim 6, wherein the take-up webs have a conical contactsurface.
 9. The motor/pump assembly of claim 7, wherein the take-up webshave a conical contact surface.
 10. A motor/pump assembly for use in amotor vehicle braking device, an electric motor; an axially followingpump driven by the latter; a drive connection, in the manner of a cardanjoint, between the motor and the pump via a coupling piece, in each casewith a positive plug receptacle for a driven-side rotor shaft end of themotor and for a drive-side pump shaft end of the pump, and an axiallyconical design of the plug receptacle and with a mutual axial prestressof the rotor shaft end and of the pump shaft end with the effect of aplay-free rotational take-up.
 11. The motor/pump assembly as claimed inclaim 10, the plug receptacle having two radially projecting axiallyrunning take-up webs on the rotor shaft end and on the pump shaft end,or on the coupling piece, and two mating take-up grooves on the couplingpiece or on the shaft ends.
 12. The motor/pump assembly as claimed inclaim 11, wherein the coupling piece comprises take-up webs and saidwebs include conical take-up surfaces.
 13. The motor/pump assembly asclaimed in claim 11, wherein the shaft ends comprise take-up webs, saidwebs having conical take-up surfaces.
 14. The motor/pump assembly asclaimed in claim 10, wherein said assembly is adapted for use in ahydraulic pump drive of an ABS braking device for a motor vehicle.